Final answer:
The first type of mammal sent to space by Russia and America was a dog.
Step-by-step explanation:
The type of mammal that was sent to space by both Russia and America for the first time was a dog. In August 1960, the Soviet Union successfully launched two dogs named Belka and Strelka into orbit and returned them to Earth alive. This achievement came after the first dog sent by the Soviets, Laika, sadly did not survive the trip.